This invention is directed to a method and apparatus for sterilizing various types of materials and/or equipment by exposure to biocidal gases such as ethylene oxide.
Ethylene oxide is widely used to sterilize a variety of products and materials. It may be used alone or in a mixture with dilutant gases such as Dichlorodifluoromethane or Carbon Dioxide. It is known that ethylene oxide exposure to humans presents a hazard as it may cause eye and skin irritation, is a human mutagen and a suspected carcinogen. In view of the potential hazards that an ethylene oxide sterilizer may present, these sterilizers are usually maintained in a room which is well ventilated so as to minimize exposure of humans to the gas. Typically an exhaust vent is provided for drawing air from the room in which the sterilizer is placed and venting that air to the atmosphere. In some systems a warning light or some other type of indicator, which operates independently of the sterilizer, is provided to warn the operator that the exhaust vent is not operating. However, there still exists the possibility that the exhaust vent will not be turned on or the exhaust vent may become nonoperational during operation of the sterilizing apparatus. This could result in an excess amount of ethylene oxide being present in the room.
Applicant has invented a method and apparatus whereby the risk of exposure to ethylene oxide or other biocidal gas is minimized when and if the exhaust vent becomes inoperative.